文件目录

#include <iostream>
using namespace std;

int main()
{
    int n, m;
    char c;
    int y;
    cin >> n >> m >> c >> y;
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= m; j++)
        {
            if (y == 1 || i == 1 || i == n || j == 1 || j == m)
                cout << c;
            else
                cout << ' ';
        }
        cout << endl;
    }
    return 0;
}